Worksheet
Curated OER

Forty Mental Math Angle Problems

For Students 10th - 11th
In this angle worksheet, students answer forty mental math questions divided into four problem sets.  These problems require students to remember angle facts and so simple calculations mentally.
Lesson Plan
Curated OER

Algebra And Trigonometry - Week 3: Law of Sines

For Teachers 12th - Higher Ed
In this law of sines worksheet, students read story problems. They use both algebra and the law of sines and cosines to solve problems. This two page worksheet contains seven problems.
Lesson Plan
Curated OER

Study Buddies: Classifying Triangles

For Teachers 4th - 5th
In this math worksheet, students analyze an informative chart about the measurement and angles of equilateral, isosceles and scalene triangles. Students then answer 5 questions about classifying triangles.
Unit Plan
Mathematics Vision Project

Module 3: Geometric Figures

For Teachers 9th - 12th Standards
It's just not enough to know that something is true. Part of a MVP Geometry unit teaches young mathematicians how to write flow proofs and two-column proofs for conjectures involving lines, angles, and triangles.
Assessment
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CCSS Math Activities

Smarter Balanced Sample Items: High School Math – Claim 3

For Teachers 9th - 12th Standards
Communication is the key. A presentation provides 25 sample items for Claim 3, Communicating Reasoning, for the Smarter Balanced High School Math assessment. Items require pupils to answer the question and provide logical reasoning to...
Lesson Plan
Curated OER

Angles and Arcs

For Teachers 9th - 10th
Students discuss the sum of central angles and use string to create them on circles. They find the measure and length of both minor and major arcs. Students give examples of concentric, similar, and congruent circles and congruent arcs.
Lesson Plan
Curated OER

Why Does ASA Work?

For Teachers 9th - 10th Standards
Your geometry learners explore Angle-Side-Angle congruence in this collaborative task. The sum of the interior angles of all triangles being one hundred eighty degrees, is the key learners will discover as they explain their reasoning...
Workbook
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Utah Education Network (UEN)

Geometric Figures and Scale Drawings

For Students 7th Standards
Scale up your lessons on geometry and ask learners to investigate conditions on triangles, scale drawings, the area and circumference of circles, and angle relationships. The resource includes activities and a homework assignment.
Lesson Plan
Curated OER

Pythagorean Theorem by Graphic Manipulation

For Teachers 7th - 9th
There are many different ways to show a proof of the Pythagorean Theorem.  Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...
Lesson Plan
Curated OER

Triangle Exterior Angles Theorem

For Teachers 7th - 9th
Learners identify the measure of missing exterior angles. In this geometry activity,students define and apply the exterior angle theorem to solve problems. They use Cabri software to create different angles and make investigations.
Lesson Plan
Curated OER

Interior and Exterior Angles of Polygons

For Teachers 9th - 10th
Students identify interior and exterior angles of polygons. In this geometry lesson, students add interior and exterior angles of polygons. They use angle theorems to solve the problems.
Lesson Plan
Curated OER

Polygon Sum Conjecture

For Teachers 9th - 10th
Students calculate the sum of the angles of a polygon. In this geometry instructional activity, students use the interior angle formula of polygon based on the number of sides of the polygon. They identify the missing angle using...
Lesson Plan
Curated OER

Lesson Exchange: Polygons (Middle, Mathematics)

For Teachers 6th - 7th
Learners discover the relationship between the sides of a polygon and the number of diagonals that can be drawn from one vertex, the number of triangles that those diagonals form, and the sum of the interior angles of that polygon.
Worksheet
Curated OER

Congruence of Triangles

For Students 10th
In this congruence of triangles worksheet, 10th graders solve 10 different problems that include determining the congruence of various triangles. First, they determine the length of two sides of a congruent triangle. Then, students...
Interactive
Curated OER

Angles in a Triangle

For Students 10th
In this geometry worksheet, 10th graders determine the measure or measures of the missing angle(s) in a triangle. The one page interactive worksheet contains four questions. Answers and hints are included. 
Lesson Plan
EngageNY

Secant Lines; Secant Lines That Meet Inside a Circle

For Teachers 9th - 12th Standards
Young mathematicians identify different cases of intersecting secant lines. They then investigate the case where secant lines meet inside a circle.
Worksheet
Curated OER

To Be a Triangle Or Not To Be a Triangle?

For Students 10th
In this triangles instructional activity, 10th graders solve and complete 10 different problems that include applying the Triangle Inequality Theorem. First, they use the illustrated triangles and the data table to test the theorem....
Lesson Plan
Curated OER

Properties of the Centers of a Triangle

For Teachers 9th - 12th Standards
High schoolers investigate properties of the four centers of a triangle and explore a special property of the circumcenter and orthocenter of a triangle. This lesson requires the use of Cabri, Jr.
Lesson Plan
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Curated OER

A Rectangle in the Coordinate Plane

For Teachers 7th - 9th Standards
A quadrilateral is drawn on the coordinate plane, and eighth grade geometers find the length of each side and the diagonals by applying the Pythagorean theorem. 
Worksheet
Curated OER

Proving Quadrilaterals

For Students 10th
In this geometry worksheet, 10th graders identify the missing angles using the polygons sum conjecture. They measure exterior and interior angles using their angle theorems. There are 63 problems.
Worksheet
Curated OER

Triangle Similarity

For Students 10th
In this triangle similarity worksheet, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles shown are...
Lesson Plan
EngageNY

Writing and Solving Linear Equations

For Teachers 8th Standards
Incorporate geometry into the solving linear equations lesson. Pupils use their knowledge of geometry to write linear equations which reinforces geometry measurement concepts while at the same time providing a familiar context for...
Lesson Plan
Curated OER

Tessellation Trial and Error

For Teachers 5th - 8th
In this interactive instructional activity, young scholars review attributes of equilateral polygons. They are introduced to the concept of a tessellation. Using protractors and pre-cut shapes, students arrange a variety of tiles to...
Worksheet
Curated OER

Geometric Shapes and Angles

For Students 10th
In this geometry worksheet, 10th graders review polygons and solve for the missing angles of trapezoids and isosceles triangles. There are 10 questions on this worksheet with an answer key.